The Red List of Mammals of South Africa, Lesotho and Swaziland Acomys spinosissimus | 1

Taxonomy

Acomys spinosissimus (Peters 1852)

ANIMALIA - CHORDATA - MAMMALIA - RODENTIA -

MURIDAE - Acomys - spinosissimus

Synonyms: Acomys selousi (De Winton 1896); Acomys

transvaalensis (Roberts 1926)

Common names: Spiny Mouse (English), Stekelmuis

(Afrikaans)

Taxonomic status: Species complex

Taxonomic notes: This species has recently been shown

to comprise a species complex including at least three

distinct cryptic species in addition to A. spinosissimus:

A. muzei, A. ngurui and A. selousi (Verheyen et al. 2011).

Acomys selousi is a separate species endemic to southern

Africa, but has not been formally described. According to

craniometric analyses by Verheyen et al. (2011), A. selousi

from South Africa (also eastern Botswana, southern parts

of Zimbabwe and Mozambique) is distinct from

A. spinosissimus, which occurs further north. We note that

Monadjem et al. (2015) describe A. selousi separately

from A. spinossimus.

Acomys spinosissimus – Spiny Mouse

Regional Red List status (2016) Least Concern

National Red List status (2004) Least Concern

Reasons for change No change

Global Red List status (2016) Least Concern

TOPS listing (NEMBA) None

CITES listing None

Endemic No

Recommended citation: MacFadyen D, Medger K. 2016. A conservation assessment of Acomys spinosissimus. In Child

MF, Roxburgh L, Do Linh San E, Raimondo D, Davies-Mostert HT, editors. The Red List of Mammals of South Africa,

Swaziland and Lesotho. South African National Biodiversity Institute and Endangered Wildlife Trust, South Africa.

Katarina Medger

Assessment Rationale

Listed as Least Concern because of its wide distribution

within the assessment region and its presence in major

protected areas, including Kruger National Park and a

number of private conservation areas. There are currently

no major identified threats that could cause overall

population decline. This species inhabits rocky areas

which are less likely to be transformed. However, we note

that once A. selousi has been formally described, this

species will need to be re-assessed.

Regional population effects: Dispersal is possible across

regions when rocky areas are connected by suitable

habitat corridors. For example, Spiny Mice have been

recorded in a grassland saddle between sandstone

outcrops (D. MacFadyen pers. obs.). However, as they are

predominantly restricted to rocky habitats, and are not as

numerous as other species (such as Micaelamys

namaquensis), they may be relatively poor dispersers.

Distribution

Within the southern African sub-region, the species occurs

widely across Zimbabwe and in Mozambique south of the

Zambezi River, and marginally in eastern Botswana

(Skinner & Chimimba 2005; Table 1). Within the

assessment region, it occurs throughout the Limpopo

Province, and northwestern parts of the North West

Province, and into parts of Gauteng and Mpumalanga

(Figure 1). It is widespread but limited to areas with

suitable rocky habitat, and is not as uniformly spread as

other rupicolous small mammal species. In the North West

Province, it was captured in Pilanesberg National Park and

Madikwe Game Reserve in the north (but not at

Borakalalo), and was captured for the first time in the

Enzelsberg and in the norite koppies at Bospoort Dam

(Power 2014). It was not captured further south (for

example, in the Magaliesberg), and thus, based on high

sampling effort, it probably does not occur there. In

Gauteng and Mpumalanga provinces this species was

readily recorded in the red sandstone areas of Ezemvelo

Nature Reserve (Gauteng) and Telperion (Mpumalanga)

(MacFadyen 2014).

Population

This species is common, but seldom seen unless actively

trapped in the right habitat and is not suspected to be

declining, although its rocky habitat is naturally

fragmented. At Telperion Nature Reserve in Mpumalanga,

the mean minimum density of the species was

5 individuals / ha and total subpopulation size was thus

estimated at 9,840 individuals (MacFadyen 2014). The

species is usually solitary, in pairs or small family groups,

so is never recorded in large numbers. Population

numbers also tend to fluctuate seasonally, becoming

more abundant in autumn (MacFadyen 2014).

Current population trend: Stable

Continuing decline in mature individuals: Unknown

As its name suggests, the hair on the Spiny

Mouse is spiny and has a prickly appearance

(Photo 1), which may be an adaptation to a

lifestyle in rocky terrain (cf. Klipspringer).

Acomys spinosissimus | 2 The Red List of Mammals of South Africa, Lesotho and Swaziland

Figure 1. Distribution records for Spiny Mouse (Acomys spinosissimus) within the assessment region

Number of mature individuals in population: Unknown

Number of mature individuals in largest subpopulation:

Unknown

Number of subpopulations: Unknown

Severely fragmented: Naturally fragmented

Habitats and Ecology

The species is largely associated with rocky terrain and

usually found living under and among boulders in rocky

habitat, favouring sheltered overhanging rocks and

exfoliated pieces of rock, occasionally using holes in

termite mounds or tree roots (Skinner & Chimimba 2005),

and sometimes recorded in areas with scattered rocks

and scree fields. In Gauteng and Mpumalanga, they have

been regularly recorded in grassy saddles between rocky

areas (MacFadyen 2014). It is not known if the species

can persist in disturbed or modified habitats.

Country Presence Origin

Botswana Extant Native

Lesotho Absent -

Mozambique Extant Native

Namibia Absent -

South Africa Extant Native

Swaziland Absent -

Zimbabwe Extant Native

It is largely nocturnal and terrestrial in habits (Hoole et al.

2012; MacFadyen 2014), although it may show some

crepuscular activity, especially on overcast days. It

reproduces seasonally during the South African spring

and summer months (Medger et al. 2010, 2012;

MacFadyen 2014), and has a litter size of two to four. Its

diet consists predominantly of grass seeds and the seeds

of other herbaceous plants, although they have been

recorded to feed on termites and other insects, including

millipedes, spiders and small snails (Vesey-Fitzgerald

1966).

The colloquial name of A. spinosissimus refers to the spiny

pelage (Photo 1), which is not soft as in other species of

murids but has a prickly appearance. The tail of the Spiny

Mouse is sparsely bristled and darker above than below.

Its skin is very thin and tears easily. Additionally, the skin

around the tail is easily lost resulting in the loss of that part

or the entire tail. Both are predator defence strategies,

which confuse the attacker and enable the mouse to

escape. Although the skin on the body grows back (Seifert

et al. 2012), the tail is permanently lost. Individuals without

tails are found frequently, which suggests that tail loss is

not detrimental to their survival. Care needs to be taken

when handling individuals.

Ecosystem and cultural services: Similar to other small

mammals, this species probably plays a role in regulating

invertebrate numbers (and thus pest outbreaks), being an

important forage species for predators (including felids,

jackals, mongooses, genets, snakes and owls) in rocky

areas, and breaking down vegetation for nest materials.

Table 1. Countries of occurrence within southern Africa

The Red List of Mammals of South Africa, Lesotho and Swaziland Acomys spinosissimus | 3

Current habitat trend: The mining sector is suspected to

be expanding rapidly in Limpopo, Mpumalanga and North

West provinces (NW READ 2014; Desmet & Schaller

2015), but the extent of impacts from this sector is

currently poorly known (V. Egan pers. comm. 2015; Lötter

2015).

Conservation

The Spiny Mouse occurs in many protected areas across

its range in South Africa, including Kruger National Park

and a number of provincial and private protected areas;

for example, Ezemvelo Nature Reserve (Gauteng),

Telperion Nature Reserve (Mpumalanga), Mapungubwe

National Park, De Beers Venetia Limpopo Nature Reserve,

Blouberg Nature Reserve and Musina Nature Reserve

(Limpopo). Large numbers are found in the Soutpansberg

region. The Soutpansberg and the Blouberg ranges are

separated from other suitable habitats and thus may

contain genetically distinct subpopulations. Another key

site may include the Waterberg region. Protected area

expansion should thus prioritise the Soutpansberg and

Waterberg regions, as they encompass large areas with

suitable habitat and potentially distinct subpopulations.

No specific interventions are currently necessary.

However, legislation regarding the protection of habitat

from mining rock (especially granite) and mitigating rock

crushing in Limpopo, Mpumalanga and North West

provinces, would benefit this species.

Recommendations for land managers and

practitioners:

No specific management plan is necessary.

Research priorities:

Taxonomic resolution: formally describing A. selousi

and re-assessing this species.

Assessment of species abundance and habitat

preference in all provinces.

Encouraged citizen actions:

Report sightings on virtual museum platforms (for

example, iSpot and MammalMAP). This species is

distinctive and easily identifiable as it looks like a

small hedgehog.

Rank Threat description Evidence in the

scientific literature

Data

quality

Scale of

study Current trend

1 3.2 Mining & Quarrying: habitat loss

from mining for gravel and rock.

Lötter et al. 2014

Desmet & Schaller 2015

Indirect

Indirect

Regional

Regional

Increasing (numbers of prospecting and

mining applications received).

Table 2. Threats to the Spiny Mouse (Acomys spinosissimus) ranked in order of severity with corresponding evidence (based on

IUCN threat categories, with regional context)

Rank Intervention description

Evidence in

the scientific

literature

Data

quality

Scale of

evidence

Demonstrated

impact

Current

conservation

projects

1 5.1 Legislation: legislation to limit area mined,

allowing for suitable habitat to remain post mining.

- Anecdotal - - None

2 1.1 Site/Area Protection: protected area expansion

in the Soutpansberg and Waterberg regions.

- Anecdotal - - None

Table 3. Conservation interventions for the Spiny Mouse (Acomys spinosissimus) ranked in order of effectiveness with

corresponding evidence (based on IUCN action categories, with regional context)

Photo 1. Sharp bristles of the Cape Spiny Mouse (Acomys

spinosissimus). Photo: R. John Power.

Use and Trade

This species is utilised for ecological research purposes

and museum records in small numbers. It is not traded or

utilised otherwise.

Threats

There are no major threats to this species as it occupies

largely inaccessible rocky areas that are unsuitable for

agriculture, livestock production and forestry. However,

mining for gravel and rock (specifically granite) could lead

to localised habitat loss and subpopulation decline.

Acomys spinosissimus | 4 The Red List of Mammals of South Africa, Lesotho and Swaziland

Medger K, Chimimba CT, Bennett NC. 2012. Seasonal changes in

reproductive development in male spiny mice (Acomys

spinosissimus) from South Africa. Mammalian Biology-Zeitschrift

für Säugetierkunde 77:153–159.

Monadjem A, Taylor PJ, Denys C, Cotterill FPD. 2015. Rodents of

Sub-Saharan Africa: A Biogeographic and Taxonomic Synthesis.

De Gruyter, Berlin, Germany.

NW READ. 2014. North West Environment Outlook Report 2013.

North West Provincial Government, Mahikeng, South Africa.

Power RJ. 2014. The Distribution and Status of Mammals in the

North West Province. Department of Economic Development,

Environment, Conservation & Tourism, North West Provincial

Government, Mahikeng, South Africa.

Seifert AW, Kiama SG, Seifert MG, Goheen JR, Palmer TM,

Maden M. 2012. Skin shedding and tissue regeneration in African

spiny mice (Acomys). Nature 489:561–565.

Skinner JD, Chimimba CT. 2005. The Mammals of the Southern

African Subregion. Third edition. Cambridge University Press,

Cambridge, UK.

Verheyen W, Hulselmans J, Wendelen W, Leirs H, Corti M. 2011.

Contribution to the systematics and zoogeography of the East-

African Acomys. Zootaxa 3059:1–35.

Vesey-Fitzgerald DF. 1966. The habits and habitats of small

rodents in the Congo River catchment region of Zambia and

Tanzania. Zoologica Africana 2:111–122.

Become more aware of habitat destruction and

protest mining applications in sensitive areas.

Avoid using harmful chemicals and insecticides.

For people who live near rocky areas, specifically

koppies, build rock gardens with lots of crevices to

create suitable habitat patches.

Learn about the importance of small mammals in a

healthy, balanced environment.

References

Desmet PG, Schaller R. 2015. North West Biodiversity Sector Plan

Technical Report. North West Department of Rural, Environment

and Agricultural Development, Mahikeng, South Africa.

Hoole C, Oosthuizen MK, Chimimba CT, Bennett NC. 2012. The

locomotory activity rhythm of the spiny mouse, Acomys

spinosissimus from southern Africa: light entrainment and

endogenous circadian rhythms. Journal of Zoology 288:93–102.

Lötter MC. 2015. Technical Report for the Mpumalanga

Biodiversity Sector Plan – MBSP. Mpumalanga Tourism & Parks

Agency, Mbombela (Nelspruit), South Africa.

MacFadyen DN. 2014. The dynamics of small mammal

populations in Rocky Highveld Grassland, Telperion, South

Africa. Ph.D. Thesis. University of Pretoria, Pretoria, South Africa.

Medger K, Chimimba CT, Bennett NC. 2010. Seasonal

reproduction in the female spiny mouse from South Africa.

Journal of Zoology 282:163–170.

Table 4. Information and interpretation qualifiers for the Spiny

Mouse (A. spinosissimus) assessment

Data sources Field studies (unpublished); indirect

information (expert knowledge);

museum records

Data quality (max) Inferred

Data quality (min) Suspected

Uncertainty resolution Author consensus

Risk tolerance Evidentiary

Data Sources and Quality

Assessors and Reviewers

Duncan MacFadyen1, Katarina Medger

2

1E. Oppenheimer & Son,

2University of Pretoria

Contributors

Nico L. Avenant1, Margaret Avery

2, Rod Baxter

3, Ara

Monadjem4, Guy Palmer

5, Peter Taylor

6, and Beryl

Wilson7

1National Museum, Bloemfontein,

2Iziko South African Museums,

3University of Venda,

4University of Swaziland,

5Western Cape

Nature Conservation Board, 6University of Venda,

7McGregor

Museum

Details of the methods used to make this assessment can

be found in Mammal Red List 2016: Introduction and

Methodology.